Enrico Fermi Architect of the Atom Bomb

Enrico Fermi, the man who designed the first ever nuclear reactor, was born in 1901, in Rome, Italy. Fermi was a brilliant student and before the age of 21 he received a PhD in physics from University of Pisa. At the age of 21, he was a full professor at the University of Rome and published his first major paper, one which concerned an abstruse branch of physics called quantum statistics. In that paper, he developed the statistical theory used to describe the behavior of large aggregations of particles of the type today referred to as fermions. Electrons, protons and neutrons, the three building blocks of which ordinary matters composed are all fermions, Fermi's theory is of considerable scientific importance. In 1933, he formulated a theory of beta decay, a type of radioactivity, which included the first quantitative discussion of the neutrino and of weak interactions, both important topics in present-day physics. Research of that kind, though not readily comprehensible by laymen, established Fermi as one of the world's leading physicists. In 1932, James Chadwick, the British physicist, had discovered a new subatomic particle, the neutron. Starting in 1934, Fermi proceeded to bombard most of the known chemical elements with neutrons. Fermi's experiments showed that many types of atoms were able to absorb neutrons, and that in many cases the atoms resulting from such a nuclear transformation were radioactive. One might have expected that it would be easier for a neutron to penetrate an atomic nucleus if the neutron were moving very rapidly. But Fermi's experiments indicated that the reverse was true, and that if the fast neutrons were first slowed down by making them pass through paraffin or water, they could then be more readily absorbed by atoms. This discovery has important application in the construction of nuclear reactors. To slow down the neutrons, the material which is used in reactors is referred to as a moderator. In 1938, Fermi was awarded with the Nobel Prize in Physics for his important research on the absorption of neutron. In 1938, when Fermi went to Stockholm, Sweden to accept his Nobel Prize, instead of returning to Italy, he went to New York, where Columbia University delighted to add one of the world's greatest scientists to its staff and offered him a position and became a citizen of America in 1944. In early 1939, it was reported by Lisa Meitner, Otto Hahn and Fritz Strassmann that the absorption of neutrons sometimes caused uranium atoms to fission. When that report came out, Fermi along with several other scientists in the world promptly realized that a fissioning uranium atom might release enough neutrons to start a chain reaction and foresaw the military potentialities of such a chain reaction. By March 1939, Fermi contacted the United States Navy and tried to interest them in the development of atomic weapons. However, it was not until several months later, after Albert Einstein had written a letter on the subject to President Roosevelt, that the United States government became interested in atomic energy. Once the American government did become interested, the scientists' first task was to construct a prototype atomic pile in order to see whether a self-sustaining chain reaction was indeed feasible. Since Fermi was the world's leading authority on neutrons, he was chosen to head the group attempting to construct the world's first nuclear reactor. Fermi worked first at Columbia University and then at the University of Chicago as a professor of nuclear studies, which now bears his name Fermi Institute. It was in Chicago, on December 2, 1942, that the nuclear reactor which had been designed and constructed under Fermi's supervision first went into successful operation. That was the true beginning of the atomic age, for that was the first time that mankind succeeded in setting off a nuclear chain reaction. Since 1945, no atomic weapons have been used in warfare, but a large number of nuclear reactors have been built to generate energy for peaceful purposes. Some reactors are used to produce useful radioisotopes, with applications in medicine and in scientific research. Reactors are also and more ominously a source of plutonium, a substance which can be used to build atomic weapons. At the end of Second World War, Fermi became a professor at the University of Chicago. He died in 1954. Fermi was married and had two children. Chemical No. 100, Fermium, is named in his honor.